1. Field
The following description relates generally to wireless communications, and more particularly to facilitating improved accuracy and reduced complexity for signal demodulation in multi-channel wireless communication.
2. Background
Wireless communication systems are widely deployed to provide various types of communication content, such as voice content, data content, and so on. Typical wireless communication systems can be multiple-access systems capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, . . . ). Examples of such multiple-access systems can include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, and the like. Additionally, the systems can conform to specifications such as third generation partnership project (3GPP), 3GPP long term evolution (LTE), ultra mobile broadband (UMB), or multi-carrier wireless specifications such as evolution data optimized (EV-DO), one or more revisions thereof, etc.
Generally, wireless multiple-access communication systems can simultaneously support communication for multiple mobile devices. Each mobile device can communicate with one or more base stations via transmissions on forward and reverse links. The forward link (or downlink) refers to the communication link from base stations to mobile devices, and the reverse link (or uplink) refers to the communication link from mobile devices to base stations. Further, communications between mobile devices and base stations can be established via single-input single-output (SISO) systems, multiple-input single-output (MISO) systems, multiple-input multiple-output (MIMO) systems, and so forth.
MIMO systems commonly employ multiple (NT) transmit antennas and multiple (NR) receive antennas for data transmission. A MIMO channel formed by the NT transmit and NR receive antennas can be decomposed into NS independent channels, which can also be referred to as spatial channels, wireless channels, wireless links, or a similar terminology, where NS≦{NT, NR}. Each of the NS independent channels corresponds to a dimension. Moreover, MIMO systems may provide improved performance (e.g., increased spectral efficiency, higher throughput and/or greater reliability) if the additional dimensionalities created by the multiple transmit and received antennas are utilized.
In addition, mobile devices can communicate with other mobile devices (and/or base stations with other base stations) in peer-to-peer wireless network configurations. These peer-to-peer wireless network configurations can enable multi-user MIMO communications, where a set of mobile devices, wireless relays, wireless repeaters, and so forth coordinate to receive data from, or transmit data to, a network via multiple antennas of the respective devices. Likewise, groups of base stations can also coordinate multiple antennas at respective base stations to transmit a stream of data to, or receive a stream of data from, one or more of the mobile devices.
While MIMO communication can lead to enhanced wireless performance, several complexities result that can reduce efficacy of such communication. As one example, conventional wireless interference and noise based on signal scattering, signal interference, signal reflections and so on can be compounded for MIMO communication. As another example, employing multiple antennas to transmit or receive a data stream can require additional processing and memory overhead for a transmit-receive chain. For instance, a MIMO system based on two transmitters and two receivers involves up to four separate spatial channels and four corresponding signal dimensions. Each bit transmitted from transmitter to receiver is therefore represented by as many as four times the wireless symbols as conventional communication. Demodulation components that de-map bits by analyzing received symbols associated with a bit can observe exponential increases in processing complexity, resulting in unmanageable processing. Accordingly, mechanisms for improving wireless signal demodulation can help to realize some of the great advantages of MIMO communication.